Mining elite loci and candidate genes for root morphology-related traits at the seedling stage by genome-wide association studies in upland cotton(Gossypium hirsutum L.)

Root system architecture plays an essential role in water and nutrient acquisition in plants,and it is significantly involved in plant adaptations to various environmental stresses.In this study,a panel of 242 cotton accessions was collected to investigate six root morphological traits at the seedling stage,including main root length(MRL),root fresh weight(RFW),total root length(TRL),root surface area(RSA),root volume(RV),and root average diameter(AvgD).The correlation analysis of the six root morphological traits revealed strong positive correlations of TRL with RSA,as well as RV with RSA and AvgD,whereas a significant negative correlation was found between TRL and AvgD.Subsequently,a genome-wide association study(GWAS)was performed using the root phenotypic and genotypic data reported previously for the 242 accessions using 56,010 single nucleotide polymorphisms(SNPs)from the CottonSNP80K array.A total of 41 quantitative trait loci(QTLs)were identified,including nine for MRL,six for RFW,nine for TRL,12 for RSA,12 for RV and two for AvgD.Among them,eight QTLs were repeatedly detected in two or more traits.Integrating these results with a transcriptome analysis,we identified 17 candidate genes with high transcript values of transcripts per million(TPM)≥30 in the roots.Furthermore,we functionally verified the candidate gene GH_D05G2106,which encodes a WPP domain protein 2in root development.A virus-induced gene silencing(VIGS)assay showed that knocking down GH_D05G2106significantly inhibited root development in cotton,indicating its positive role in root system architecture formation.Collectively,these results provide a theoretical basis and candidate genes for future studies on cotton root developmental biology and root-related cotton breeding.

Genetic dissection and origin of pleiotropic loci underlying multilevel fiber quality traits in upland cotton(Gossypium hirsutum L.)

Cotton fiber quality is a persistent concern that determines planting benefits and the quality of finished textile products.However,the limitations of measurement instruments have hindered the accurate evaluation of some important fiber characteristics such as fiber maturity,fineness,and neps,which in turn has impeded the genetic improvement and industrial utilization of cotton fiber.Here,12 single fiber quality traits were measured using Advanced Fiber Information System(AFIS)equipment among 383 accessions of upland cotton(Gossypium hirsutum L.).In addition,eight conventional fiber quality traits were assessed by the High Volume Instrument(HVI)System.Genome-wide association study(GWAS),linkage disequilibrium(LD)block genotyping and functional identification were conducted sequentially to uncover the associated elite loci and candidate genes of fiber quality traits.As a result,the previously reported pleiotropic locus FL_D11 regulating fiber length-related traits was identified in this study.More importantly,three novel pleiotropic loci(FM_A03,FF_A05,and FN_A07)regulating fiber maturity,fineness and neps,respectively,were detected based on AFIS traits.Numerous highly promising candidate genes were screened out by integrating RNA-seq and qRT-PCR analyses,including the reported GhKRP6 for fiber length,the newly identified GhMAP8 for maturity and GhDFR for fineness.The origin and evolutionary analysis of pleiotropic loci indicated that the selection pressure on FL_D11,FM_A03 and FF_A05 increased as the breeding period approached the present and the origins of FM_A03 and FF_A05 were traced back to cotton landraces.These findings reveal the genetic basis underlying fiber quality and provide insight into the genetic improvement and textile utilization of fiber in G.hirsutum.

Evaluation of a Novel 32 X-STR Loci Multiplex System in the Forensic Application

The AGCU X Plus STR system is a newly developed multiplex PCR kit that detects 32 X-chromosomal STR loci simultaneously.These are DXS6807,DXS9895,linkage group 1(DXS10148,DXS10135,DXS8378),DXS9902,DXS6795,DXS6810,DXS10159,DXS10162,DXS10164,DXS7132,linkage group 2(DXS10079,DXS10074,DXS10075),DXS981,DXS6800,DXS6803,DXS6809,DXS6789,DXS7424,DXS101,DXS7133,GATA172D05,GATA165B12,linkage group 3(DXS10103,HPRTB,DXS10101),GATA31E08 and linkage group 4(DXS8377,DXS10134,DXS7423).A major advantage of this kit is that it takes into account linkage between loci,in addition to detecting more X-STR loci.In order to evaluate the forensic application of 32 X-STR fl uorescence amplifi cation system,PCR settings,sensitivity,species specifi city,stability,DNA mixtures,concordance,stutter,sizing precision,and population genetics investigation were evaluated according to the Scientific Working Group on DNA Analysis Methods(SWGDAM)developmental validation guidelines.The study showed that the genotyping results of each locus were signifi cantly accurate when the DNA template was at least 62.5 pg.Complete profi les were obtained for the 1∶1 and 1∶3 combinations.A total of 209 unrelated individuals from Southern Chinese Han community,consisting of 84 females and 125 males,were selected for population studies,and 285 allele profi les were detected from 32 X-STR loci.The polymorphism information content(PIC)ranged from 0.2721 in DXS6800,to 0.9105 in DXS10135,with an average of 0.6798.DXS10135(PIC=0.9105)was the most polymorphic locus,with discrimination power(DP)of 0.9164 and 0.9871 for the male and female.The cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) valu es were all greater than 0.999999999.There were 78 different DXS10103-HPRTB-DXS10101 haplotypes among the 125 males,and the haplotype diversity was 0.9810.There was no signifi cant difference in the cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) values whether considering linkage or not.In summary,the new X-STR multiplex typing system is effective and reliable,which can be useful in human genetic analysis and kinship testing as a potent complement to autosomal STR typing.

Analyses and identifications of quantitative trait loci and candidate genes controlling mesocotyl elongation in rice

Rice direct seeding has the significant potential to save labor and water,conserve environmental resources,and reduce greenhouse gas emissions tremendously.Therefore,rice direct seeding is becoming the major cultivation technology applied to rice production in many countries.Identifying and utilizing genes controlling mesocotyl elongation is an effective approach to accelerate breeding procedures and meet the requirements for direct-seeded rice(DSR) production.This study used a permanent mapping population with 144 recombinant inbred lines(RILs) and 2 828 bin-markers to detect quantitative trait loci(QTLs) associated with mesocotyl length in 2019 and 2020.The mesocotyl lengths of the rice RILs and their parents,Lijiangxintuanheigu(LTH) and Shennong 265(SN265),were measured in a growth chamber at 30°C in a dark environment.A total of 16 QTLs for mesocotyl length were identified on chromosomes 1(2),2(4),3(2),4,5,6,7,9,11(2),and 12.Seven of these QTLs,including qML1a,qML1b,qML2d,qML3a,qML3b,qML5,and qML11b,were reproducibly detected in both years via the interval mapping method.The major QTL,qML3a,was reidentified in two years via the composite interval mapping method.A total of 10 to 413 annotated genes for each QTL were identified in their smallest genetic intervals of 37.69 kb to 2.78 Mb,respectively.Thirteen predicted genes within a relatively small genetic interval(88.18 kb) of the major mesocotyl elongation QTL,qML3a,were more thoroughly analyzed.Finally,the coding DNA sequence variations among SN265,LTH,and Nipponbare indicated that the LOC_Os03g50550 gene was the strongest candidate gene for the qML3a QTL controlling the mesocotyl elongation.This LOC_Os03g50550 gene encodes a mitogen-activated protein kinase.Relative gene expression analysis using qRT-RCR further revealed that the expression levels of the LOC_Os03g50550 gene in the mesocotyl of LTH were significantly lower than in the mesocotyl of SN265.In conclusion,these results further strengthen our knowledge about rice’s genetic mechanisms of mesocotyl elongation.This investigation’s discoveries will help to accelerate breeding programs for new DSR variety development.

The eQTL colocalization and transcriptome‑wide association study identify potentially causal genes responsible for economic traits in Simmental beef cattle

Background A detailed understanding of genetic variants that affect beef merit helps maximize the efficiency of breeding for improved production merit in beef cattle.To prioritize the putative variants and genes,we ran a com-prehensive genome-wide association studies(GWAS)analysis for 21 agronomic traits using imputed whole-genome variants in Simmental beef cattle.Then,we applied expression quantitative trait loci(eQTL)mapping between the genotype variants and transcriptome of three tissues(longissimus dorsi muscle,backfat,and liver)in 120 cattle.Results We identified 1,580 association signals for 21 beef agronomic traits using GWAS.We then illuminated 854,498 cis-eQTLs for 6,017 genes and 46,970 trans-eQTLs for 1,903 genes in three tissues and built a synergistic network by integrating transcriptomics with agronomic traits.These cis-eQTLs were preferentially close to the transcription start site and enriched in functional regulatory regions.We observed an average of 43.5%improvement in cis-eQTL discovery using multi-tissue eQTL mapping.Fine-mapping analysis revealed that 111,192,and 194 variants were most likely to be causative to regulate gene expression in backfat,liver,and muscle,respectively.The transcriptome-wide association studies identified 722 genes significantly associated with 11 agronomic traits.Via the colocalization and Mendelian randomization analyses,we found that eQTLs of several genes were associated with the GWAS signals of agronomic traits in three tissues,which included genes,such as NADSYN1,NDUFS3,LTF and KIFC2 in liver,GRAMD1C,TMTC2 and ZNF613 in backfat,as well as TIGAR,NDUFS3 and L3HYPDH in muscle that could serve as the candidate genes for economic traits.Conclusions The extensive atlas of GWAS,eQTL,fine-mapping,and transcriptome-wide association studies aid in the suggestion of potentially functional variants and genes in cattle agronomic traits and will be an invaluable source for genomics and breeding in beef cattle.

Robust identification of regulatory variants(eQTLs)using a differential expression framework developed for RNA‑sequencing

Background A gap currently exists between genetic variants and the underlying cell and tissue biology of a trait,and expression quantitative trait loci(eQTL)studies provide important information to help close that gap.However,two concerns that arise with eQTL analyses using RNA-sequencing data are normalization of data across samples and the data not following a normal distribution.Multiple pipelines have been suggested to address this.For instance,the most recent analysis of the human and farm Genotype-Tissue Expression(GTEx)project proposes using trimmed means of M-values(TMM)to normalize the data followed by an inverse normal transformation.Results In this study,we reasoned that eQTL analysis could be carried out using the same framework used for dif-ferential gene expression(DGE),which uses a negative binomial model,a statistical test feasible for count data.Using the GTEx framework,we identified 35 significant eQTLs(P<5×10^(–8))following the ANOVA model and 39 significant eQTLs(P<5×10^(–8))following the additive model.Using a differential gene expression framework,we identified 930 and six significant eQTLs(P<5×10^(–8))following an analytical framework equivalent to the ANOVA and additive model,respectively.When we compared the two approaches,there was no overlap of significant eQTLs between the two frameworks.Because we defined specific contrasts,we identified trans eQTLs that more closely resembled what we expect from genetic variants showing complete dominance between alleles.Yet,these were not identified by the GTEx framework.Conclusions Our results show that transforming RNA-sequencing data to fit a normal distribution prior to eQTL analysis is not required when the DGE framework is employed.Our proposed approach detected biologically relevant variants that otherwise would not have been identified due to data transformation to fit a normal distribution.

Genetic susceptibility loci of lung cancer are associated with malignant risk of pulmonary nodules and improve malignancy diagnosis based on CEA levels

Objective:The heightened prevalence of pulmonary nodules(PN)has escalated its significance as a public health concern.While the precise identification of high-risk PN carriers for malignancy remains an ongoing challenge,genetic variants hold potentials as determinants of disease susceptibility that can aid in diagnosis.Yet,current understanding of the genetic loci associated with malignant PN(MPN)risk is limited.Methods:A frequency-matched case-control study was performed,comprising 247 MPN cases and 412 benign NP(BNP)controls.We genotyped 11 established susceptibility loci for lung cancer in a Chinese cohort.Loci associated with MPN risk were utilized to compute a polygenic risk score(PRS).This PRS was subsequently incorporated into the diagnostic evaluation of MPNs,with emphasis on serum tumor biomarkers.Results:Loci rs10429489G>A,rs17038564A>G,and rs12265047A>G were identified as being associated with an increased risk of MPNs.The PRS,formulated from the cumulative risk effects of these loci,correlated with the malignant risk of PNs in a dose-dependent fashion.A high PRS was found to amplify the MPN risk by 156%in comparison to a low PRS[odds ratio(OR)=2.56,95%confidence interval(95%CI),1.40−4.67].Notably,the PRS was observed to enhance the diagnostic accuracy of serum carcinoembryonic antigen(CEA)in distinguishing MPNs from BPNs,with diagnostic values rising from 0.716 to 0.861 across low-to high-PRS categories.Further bioinformatics investigations pinpointed rs10429489G>A as an expression quantitative trait locus.Conclusions:Loci rs10429489G>A,rs17038564A>G,and rs12265047A>G contribute to MPN risk and augment the diagnostic precision for MPNs based on serum CEA concentrations.

跨境知识产权侵权纠纷的域外法律适用

各国在处理跨境知识产权侵权纠纷的域外法律适用问题时主要采取两种模式,即单向域外适用模式与双向域外适用模式。前者更多地是将知识产权视为一种政策性的特权,在处理域外侵权行为时往往不会发生外国的知识产权法被本国法院所适用的情况,但会出现本国知识产权法适用于发生在域外行为的情形;后者更多地是将知识产权视为一种民事权利,对于发生在域外的行为,本国法院既可能适用本国知识产权法律,也可能适用外国知识产权法律,是否发生外国法律的适用取决于一国立法对较为中立的连接点的界定。我国在立法上采取了以“被请求保护地”为连接点的双向域外适用模式,但是在司法实践中往往并不进行法律选择而是径行适用中国知识产权法律。这将导致在司法上采取了将中国知识产权法律适用于域外行为的单向域外适用模式。我国应在跨境知识产权侵权纠纷的域外法律适用问题上回归双向域外适用模式,并在具体纠纷裁判中丰富和明确“被请求保护地”的含义,同时设置“无所不在”侵权行为的特殊法律适用规则,限制当事人共同选择适用法的范围以及确定公共秩序在准据法选择中的适用,以实现维护本国利益的目的。

实验用大林姬鼠种群微卫星标记开发及遗传特性分析

目的 开发大林姬鼠多态性微卫星标记,丰富大林姬鼠遗传数据,为大林姬鼠遗传质量控制及基因定位等工作奠定基础。方法 基于大林姬鼠基因组序列筛选微卫星位点,挖掘微卫星引物,通过多重PCR技术分析群体的遗传多样性。结果 成功开发出30个微卫星标记,利用60份大林姬鼠基因组DNA对30个微卫星位点进行评价,共检测出152个等位基因,平均每个位点有5.067个等位基因;平均观察杂合度为0.592;平均香农指数为1.265;平均多态信息含量为0.598。结论 基于本研究所开发的微卫星位点具有较好的多态性,能有效分析大林姬鼠群体的遗传多样性,适合为建立大林姬鼠遗传质量标准和遗传质量检测方法奠定基础。

小麦茎基腐病抗性位点研究进展

对小麦茎基腐病(FCR)抗性位点研究进行综述。目前,在小麦所有的21条染色体上定位了140个抗性QTL,含10个抗性基因,虽然报道的抗性位点很多,但主效位点不明确,严重影响小麦FCR抗性改良进程。分析了小麦FCR抗性位点研究中的主要问题,提出了统一抗性鉴定标准、增强成株期抗性研究等建议,以明确抗FCR主效位点/基因并开发分子标记,通过分子标记辅助选择促进FCR抗性改良进程。

籼粳亚种间育性位点分型及籼粳杂交稻育性位点模式研究

【目的】了解我国籼稻、粳稻材料及籼粳杂交稻组合中亚种间育性位点的分布,建立实现亚种间育性亲和所需遗传位点模式,探索新的籼粳杂交稻组合模式,为亚种间亲和材料改良和籼粳育性亲和分子设计育种打下基础。【方法】通过筛选得到育性位点的籼粳分型标记对我国水稻材料进行育性位点的籼粳分型检测,挑选部分籼稻、粳稻亲本进行杂交并统计分析F1代花粉育性和结实率。【结果】籼稻和粳稻之间在所有育性位点均存在少量相互渗入。由于籼稻育性位点渗入,粳稻可以分为Ⅰ型(所有位点均为粳型)和Ⅱ型(Sc^(i)、Sd^(i)和Se^(i),上标i代表来自籼稻)。S5不亲和时籼粳杂交稻结实率约为50%,亲和时结实率约为80%。Sa、Sb、Sc或Sd单个位点杂合对于花粉育性影响较小,但Se/pf12/RHS12单个位点杂合时显著降低花粉育性。籼粳杂交稻材料检测结果表明其育性位点的基本模式是S5和部分花粉育性位点纯合/亲和。带有S5^(n)的籼稻两系不育系深08S与粳稻Ⅱ型材料的杂交F_(1)代的花粉育性和结实率正常。【结论】S5是控制雌配子育性的核心位点。影响雄配子育性的位点具有累加效应,其中Se可能是不可缺少的重要位点。S5+Se与Sa、Sb、Sc、Sd任意两个纯合位点可能是实现籼粳亚种间育性亲和的基本遗传位点模式。以广亲和两系籼稻不育系为母本,常规粳稻为父本的“籼不粳恢”籼粳杂交模式是一个可行的亚种间组合模式。

涉外知识产权法律适用中被请求保护地法之界定

知识产权法律适用中被请求保护地法起源于《伯尔尼公约》第5条第2款。对《伯尔尼公约》第5条,学者之间形成了“被请求保护地法说”、“来源国法说”和“非冲突规范说”三种不同观点。在《伯尔尼公约》的影响下,各国在相关的国内知识产权冲突法中开始逐步采用被请求保护地的法律。但《伯尔尼公约》第5条第2款与生俱来的争议决定了被请求保护地作为连结点在含义上的模糊性。为此,一些学术机构分别制定了有关知识产权法律适用规则的建议稿,这些规则及解释对于理解被请求保护地具有重大参考价值。2010年颁布的《中华人民共和国涉外民事关系法律适用法》第48条、第50条规定以被请求保护地法作为涉外知识产权法律适用的一般原则。然而,在司法实践中,法院对被请求保护地法的适用存在分歧,带来法律适用的不确定性和不可预见性。我国应该借鉴被请求保护地法在有关国际法律文件中的具体规定,在司法实践中,依据不同类型的知识产权案件,对其含义分别作不同界定。

论我国知识产权确权与保护冲突规范的不足与完善

包括《中华人民共和国涉外民事关系法律适用法》在内的许多国家或地区的冲突法都将“被请求保护地”作为确定涉外知识产权确权和保护案件准据法的重要连接点。“被请求保护地”的法律概念早见于《伯尔尼公约》第5条中“被要求给予保护的国家”的表达,其后续发展与涉外知识产权案件的本质特征紧密相关,应被释义为“原告诉请保护之知识产权有效地”或“双方讼争的知识产权有效地”,且被请求保护地法只在特定情形下才与权利登记地法、法院地法或侵权行为地法重合,但是“被请求保护地”与这些连接点具有完全不同的法律意义。在司法实践中,对“被请求保护地”的认定存在逻辑错误的情况较为常见,且“被请求保护地”目前已被特定化。此外,《法律适用法》第50条的适用顺序仍然存在不明确性,并且规则的公平性存疑。因此需要通过司法解释的形式来明确“被请求保护地”的释义和认定标准,将其与类似的连接点进行明确区分,以增加司法实践的确定性。此外,还需要明确《法律适用法》第50条中有限意思自治原则和被请求保护地法的适用顺序以及第50条和第44条的适用顺序,以进一步化解第50条存在的公平性问题。

基于高通量测序的北柴胡根转录组SSR位点信息分析

以北柴胡根为试材,采用高通量转录组测序方法,获得uingene序列信息,研究分析SSR分布、基元特征,设计、验证EST-SSR引物的有效性,为开发、丰富EST-SSR分子标记奠定基础。结果表明:从北柴胡根转录组中共筛选到31176个SSR位点,分布于21732条unigenes,出现的频率为20.08%,分布密度为3.20个/10 kb,主要重复基元类型以二核苷酸最为丰富,共21056个,占SSR位点总数的67.54%;其次是单核苷酸和三核苷酸,分别占总SSR的19.05%和12.07%;四核苷酸~六核苷酸重复基元数量均较少。不同核苷酸基序类型共有131种基元,重复基元次数在5~11次的数量最多,占SSR总数的91.7%,且长度基本小于15 bp,其中AT/AT和AC/GT这两种基元在二核苷酸中出现频率最高。2064条和1004条含有SSR位点的unigenes分别注释到GO和KEGG通路,获得注释的基因功能主要与基础代谢相关。从22090对具有潜在多态性的EST-SSR引物中,随机挑选20对引物对3个北柴胡种质DNA进行PCR扩增,扩增成功率最高达85%。北柴胡根转录组SSR位点丰富、可用性较强,将促进柴胡的种质资源评价及分子标记辅助育种等工作。

鲜食葡萄果实单萜合成关键基因的eQTL分析

【目的】通过对鲜食葡萄果实单萜合成关键基因进行eQTL定位及候选基因挖掘,深入了解单萜合成调控机制,为优良玫瑰香味葡萄新品种培育及种质改良奠定基础。【方法】以‘摩尔多瓦’ב瑞都香玉’F1代群体及亲本为供试材料,分别在转色期和成熟期采集葡萄果实样品;利用实时荧光定量qPCR技术对7个单萜合成途径基因(VvDXS1、VvDXS3、VvDXR、VvHDR、VvLiner、VvTerp和VvGermD)的表达量进行检测获得表达性状表型数据;基于区间作图法,采用MapQTL6.0软件,对单萜基因表达性状进行eQTL定位分析;将eQTL连锁标记定位到基因组区域,通过Ensembl Plants和NCBI数据库进行基因注释;利用葡萄全基因组芯片技术检测不同发育时期亲本果实样品中候选基因的表达谱。【结果】7个单萜合成基因表达量在F1代群体中呈现连续分布数量遗传特征;各个单萜基因表达之间具有显著的相关性;在转色期,7个表达性状一共定位到13个eQTL,主要位于1号、6号、14号、16号、17号、10号和12号等染色体上,表型解释率介于12.2%-23.5%。其中位于14号染色体的eQTL(qDXS1-v14、qHDR-v14-1和qTerp-v14)覆盖相同的遗传区间57.582-76.979 cM,qLiner-v10、qTerp-v10和qGermD-v10共定位到10号染色体相同的遗传区间;在成熟期,共检测到16个eQTL,主要位于1号、6号、12号、8号、13号和19号等染色体。qDXS1-m6-2、qDXR-m6-2、qLiner-m6和qGermD-m6共定位到6号染色体139.212-143.161 cM遗传区间;针对成熟期与转色期各个基因的表达量比值变化进行定位分析,共检测到18个eQTL,分别位于1号、3号、7号、10号、12号、15号和19号等染色体。定位于12号染色体的qDXS1-r12-1、qDXR-r12-1、qHDR-r12、qLiner-r12和qGermD-r12覆盖相同的遗传区间6.330-6.967 cM。对多个基因表达性状共定位的eQTL区域进行基因注释,共筛选到90个转录因子基因,表达谱及相关性分析最终确定11候选基因。其中4个候选基因(VIT_06s0009g01380、VIT_14s0006g02290、VIT_12s0028g01170和VIT_15s0046g00290)与激素信号通路调控相关,一个候选基因(VIT_12s0028g01110)编码光敏色素作用因子与光响应相关,还有一些编码Myb类、WRKY类转录因子或者未知功能蛋白基因。【结论】在两个不同的生长发育期共检测到37个与单萜合成基因表达性状连锁的eQTL,主要定位于6号、10号、12号和14号染色体。基于基因注释和表达谱分析结果,确定了包含VIT_06s0009g01380和VIT_14s0006g02290在内的11个可能的候选基因,这些候选基因与多个单萜基因表达高度相关。

遗传与基因表达数据的整合——eQTL的方法及应用

高通量的基因型分析和芯片技术的发展使人们能够进一步研究哪些遗传差异最终影响基因的表达。通过表达数量性状座位(eQTL)作图方法可对基因表达水平的遗传基础进行解析。与传统的QTL分析方法一样,eQTL的主要目标是鉴别表达性状座位所在的染色体区域。但由于表达谱数据成千上万,而传统的QTL分析方法最多分析几十个性状,因此需要考虑这类实验设计的特点以及统计分析方法。本文详细介绍了eQTL定位过程及其研究方法,重点从个体选择、基因芯片实验设计、基因表达数据的获得与标准化、作图方法及结果分析等方面进行了综述,指出了当前eQTL研究存在的问题和局限性。最后介绍了eQTL研究在估计基因表达遗传率、挖掘候选基因、构建基因调控网络、理解基因间及基因与环境的互作的应用进展。

Identification of Quantitative Trait Loci for Anthesis-Silking Interval and Yield Components Under Drought Stress in Maize

A genetic linkage map with 89 SSR marker loci was constructed based on a maize (Zea mays L.) population consisting of 184 F-2 individuals from the cross, Huangzao 4 X Ye 107. The 184 F-3 families were evaluated in the field under well-watered and drought-stressed regimes in Shanxi Province of China. The objectives of the study were to identify genetic segments responsible for the expression of anthesis-silking interval (ASI), ear setting and grain yield, and to examine if the quantitative trait loci (QTLs) for ASI or yield components can be used in marker-assisted selection (MAS) to improve grain yield under drought conditions. Results showed that under well-watered and drought-stressed regimes, three and two QTLs involved in the expression of ASI were detected on chromosomes 1, 2 and 3, and 2 and 5, respectively. Under well-watered regime, two QTLs for ear setting were detected on chromosomes 3 and 6, explaining about 19.9% of the phenotypic variance, and displayed additive and partial dominant effects, respectively. Under drought-stressed condition, four QTLs for ear setting were detected on chromosomes 3, 7 and 10, which were responsible for interpreting 60.4% of the phenotypic variance, and showed dominant or partial dominant effects. Under well-watered condition, four QTLs controlling grain yield were identified on chromosomes 3, 6 and 7, while five QTLs were identified under drought stress on chromosomes 1, 2, 4 and 8. The gene action was of additive or partial dominant effects, and each QTL could explain 7.3% to 22.0% of the phenotypic variance, respectively. Under drought conditions, ASI and ear setting percentage were highly correlated with grain yield, which can be used as secondary traits for grain yield selection. Based on linked markers detected and gene action analyzed, an MAS strategy for yield improvement under drought condition could be established, which consists of QTLs contributing to decreased ASI and to increased ear setting and grain yield, respectively.

ADAMTS-7基因rs3825807及rs1994016位点多态性与KD发病及CAL的关联性分析

目的分析ADAMTS-7基因rs3825807、rs1994016位点多态性与川崎病(KD)发病及其冠状动脉损伤(CAL)是否存在关联性。方法选取KD患儿100例为KD组,健康体检儿童100例为健康组。提取两组外周血DNA进行基因测序,比较两组ADAMTS-7基因rs3825807位点及rs1994016位点的多态性差异。KD组根据是否存在冠状动脉损伤分为冠状动脉损伤组(KD-CAL组)和无冠状动脉损伤组(KD-NCAL组),比较两组ADAMTS-7基因rs3825807位点及rs1994016位点的多态性差异。结果KD组与健康组比较,KD-NCAL组与KD-CAL组比较,ADAMTS-7基因rs3825807位点A、G等位基因频率和AA、AG、GG基因型频率以及rs1994016位点C、T等位基因频率和CC、CT、TT基因型频率差异均无统计学意义(P>0.05)。结论ADAMTS-7基因rs3825807、rs1994016位点多态性与KD的发病及CAL不存在明显关联性。

用于玉米品种真实性鉴定的最优核心SNP位点集的研发

品种真实性是种子质量监测的一个重要指标。为建立准确可靠、快速简便、高通量、低成本的玉米品种真实性鉴定技术,本文利用200个核心SNP位点构建的5816个玉米杂交品种,3274个自交系的指纹数据,基于遗传算法、品种识别率评估确定了一套高鉴别力的核心SNP位点集,包含96个SNP位点。这96个SNPs全部位于基因内区域,相对均匀分布在10对染色体上。采用上述杂交品种和自交系的指纹数据评估显示这96个位点具有较高多态性和品种区分能力,PIC、MAF、DP平均值分别为0.36、0.40、0.60和0.36、0.39、0.48,对杂交品种、自交系的品种识别率达到99.14%和99.24%。两两样品成对比较结果显示,99.99%的品种间差异位点数目≥3个,杂交品种和自交系中96.74%和95.67%的成对比较差异位点数目集中在30~65个和30~60个。基于221个主推杂交品种的40个SSR位点、96个SNP位点的基因型数据分析结果显示,这2组标记集的鉴定结果具有较高的一致性。综上所述,本研究报道了一套具有位点数量最少、区分能力最强,兼容多平台、适于自动化分型等优点的最优核心SNP集。期望位点集将在玉米品种真实性监测、种子质量控制中得到广泛应用,进而维护玉米种子市场秩序、保障育种者权利以及保护农民利益。

不同地区红螯螯虾(Cherax quadricarinatus)养殖群体遗传多样性分析

为了解国内广东省湛江市、广东省佛山市、广东省惠州市、广西自治区南宁市、浙江省湖州市5个地区红螯螯虾养殖群体的遗传结构,我们鉴定了红螯螯虾8个微卫星位点。利用8个微卫星标记对5个地区的红螯螯虾养殖群体进行了遗传分析,8对引物在150个样本个体中共检测出237个等位基因。所有8个微卫星的等位基因数范围为2~10,平均为6.05。H_(o)和H_(e)平均值分别为0.490和0.614。每组的等位基因数在6.000(广西南宁GXNN)到6.625(广东佛山GDFS)之间。所有群体中平均H e在0.593(广东惠州GDHZ)到0.646(广东湛江GDZJ)之间。由此可以看出种群的遗传多样性并未显著降低。F_(is)、F_(st)值、分子方差分析(AMOVA)结果显示,这些红螯螯虾群体大部分的遗传变异来源于种群内部,并且各个群体都保持着较高水平的遗传距离,其中GDZJ和ZJHZ群体之间遗传距离最大(0.1077)。推测导致这些差异的产生可能是随机遗传漂变和人工选择。